The Whole Tone Scale
The Whole tone scale is what you will need if you want to create a dreamy watery type sound, you know those scenes in movies where the person goes from reality to a dream, and you hear that sound; usually it's this scale played over a few octaves from the bottom to the top with lots of sustain.
The scale consists of all whole tones; yes you probably already knew that going by the name but anyway as long as you don't play any semitones then you'll be playing the whole tone scale.
The Fingering for PianoRight hand fingering for the first example over two octaves is
Right hand fingering for the second example over two octaves is
Left hand fingering for the first example over two octaves is
Now that you have the notes and fingering for the whole tone scale start experimenting with it and try and work out ways to incorporate it into your playing. An example would be to play a 2, 5, 1, chord progression in the key of C, if you don't know what that is then don't worry here are the chords.
(D minor 7) then (G dominant 7 flat 5) then finally it resolves to (C Major 7) The best place to use the scale would be when you play the (G dominant 7 flat 5) chord and in this example you would use the whole tone scale that goes from F to F (the second one)